CSE 142 Sample Final Exam 1 based on Spring 2005 s final thanks to Stuart Reges 1 Array Mystery Consider the following method public static void arrayMystery int a for int i 1 i a length i a i i a i 1 a i Indicate in the right hand column what values would be stored in the array after the method arrayMystery executes if the integer array in the left hand column is passed as a parameter to it Original Contents of Array Final Contents of Array int a1 7 arrayMystery a1 int a2 4 3 6 arrayMystery a2 int a3 7 4 8 6 2 arrayMystery a3 int a4 10 2 5 10 arrayMystery a4 int a5 2 4 1 6 2 8 arrayMystery a5 1 of 12 2 Reference Semantics Mystery The following program produces 4 lines of output Write the output below as it would appear on the console public class BasicPoint int x int y public BasicPoint x 2 y 2 public class ReferenceMystery public static void main String args int a 7 int b 9 BasicPoint p1 new BasicPoint BasicPoint p2 new BasicPoint addToXTwice a p1 System out println a b p1 x p2 x addToXTwice b p2 System out println a b p1 x p2 x public static void addToXTwice int a BasicPoint p1 a a a p1 x a System out println a p1 x 2 of 12 3 Inheritance Mystery Assume that the following classes have been defined public class A extends B public void method2 System out print a 2 method1 public class C public String toString return c public class B extends C public String toString return b public void method2 System out print b 2 super method2 public void method1 System out print c 1 public void method2 System out print c 2 public class D extends B public void method1 System out print d 1 method2 Given the classes above what output is produced by the following code C elements new A new B new C new D for int i 0 i elements length i System out println elements i elements i method1 System out println elements i method2 System out println System out println 3 of 12 4 File Processing Write a static method named printStrings that takes as a parameter a Scanner holding a sequence of integer string pairs and that prints to System out one line of output for each pair with the given String repeated the given number of times For example if the Scanner contains the following data 6 fun 3 hello 10 2 25 4 wow your method should produce the following output fun fun fun fun fun fun hellohellohello 2525 wow wow wow wow Notice that there is one line of output for each integer string pair The first line has 6 occurrences of fun the second line has 3 occurrences of hello the third line has 10 occurrences of the fourth line has 2 occurrences of 25 the fifth line has 4 occurrences of wow Notice that there are no extra spaces included in the output You are to exactly reproduce the format of this sample output You may assume that the input values always come in pairs with an integer followed by a String which itself could be numeric such as 25 above If the Scanner is empty no integer string pairs your method should produce no output 4 of 12 5 File Processing Write a static method named reverseLines that accepts a Scanner containing an input file as a parameter and that echoes the input file to System out with each line of text reversed For example given the following input file If this method works properly the lines of text in this file will be reversed Remember that some lines might be blank Your method should print the following output ylreporp skrow dohtem siht fI elif siht ni txet fo senil eht desrever eb lliw knalb eb thgim senil emos taht rebmemeR Notice that some of the input lines can be blank lines 5 of 12 6 Array Programming Write a static method isAllEven that takes an array of integers as a parameter and that returns a boolean value indicating whether or not all of the values are even numbers true for yes false for no For example if a variable called list stores the following values int list 18 0 4 204 8 4 2 18 206 1492 42 Then the call of isAllEven list should return true because each of these integers is an even number If instead the list had stored these values int list 2 4 6 8 10 208 16 7 92 14 Then the call should return false because although most of these values are even the value 7 is an odd number 6 of 12 7 Array Programming Write a static method named isUnique that takes an array of integers as a parameter and that returns a boolean value indicating whether or not the values in the array are unique true for yes false for no The values in the list are considered unique if there is no pair of values that are equal For example if a variable called list stores the following values int list 3 8 12 2 9 17 43 8 46 203 14 97 10 4 Then the call of isUnique list should return true because there are no duplicated values in this list If instead the list stored these values int list 4 7 2 3 9 12 47 19 308 3 74 Then the call should return false because the value 3 appears twice in this list Notice that given this definition a list of 0 or 1 elements would be considered unique 7 of 12 8 Critters Write a class Ostrich that extends the Critter class from the Critters assignment including its getMove and getColor methods An Ostrich object first stays in the same place for 10 moves then moves 10 steps to either the WEST or the EAST then repeats In other words after sitting still for 10 moves the ostrich randomly picks to go west or east then walks 10 steps in that same direction Then it stops and sits still for 10 moves and repeats Whenever an Ostrich is moving that is whenever its last call to getMove returned a direction other than Direction CENTER its color should be white Color WHITE As soon as it stops moving and initially when it first appears in the critter world its color should be cyan Color CYAN When randomly choosing west vs east the two directions should be equally likely You may add anything needed fields other methods to implement the above behavior appropriately All other critter behavior not discussed here uses the default values 8 of 12 9 Classes and Objects Suppose that you are provided with a pre written class Date as described at right The headings are shown but not the method bodies to save space Assume that the fields constructor and methods shown are already implemented You may refer to them or use them in solving this problem if necessary Each Date object stores a …